How does an HST compare in pulling power with the same tractor and a gear trans?

[Sawyer Rob]

You are correct. Just a pump and the operator controls the flow of oil (manually or by electronic means) to the hydraulic motors, one on each side.

There's NO comparing a dozer hystat to a tractor hystat, other than the name!!!

SR

 

[GSVette]

HST are nice and convenient. I've run both in many forms, but nothing that would compare to one another. I can say, that I do prefer the gear tractor over HST. I get a gas peddle, which for me, is nice when doing quick operations, like FEL work or moving things around the yard. The tractor 'idles' (high idle, around 1500rmp due to DPF garbage) when not doing the actual work. I do know there are tractors with a smart/synchronized HST peddle option that will rev up the engine more as your press down more on the go button. See the new LS MT3 series. I am sure there are many more like it.

Also, the HST models have extra filters, which is more money and more of a pain in the long run. Not to mention that buying new, HST are typically more expensive.

But for me, I'd drive an HST, but prefer a gear. And that, I think, is the crutch of the issue: what do you prefer?

That does not address the OP's question though. He wanted to know which tractor would pull better. I dont have a good side-by-side comparison to offer. But driving a gear tractor doing field work is much nicer.. for me. YMMV

Since we’re relatively close-we need to test this theory out!! We’ll back my XR4155HC and your 50 gear up to each other, chain’em up and see who drags who!!! That’ll settle this question once and for all!!

 

[CobyRupert]

Since we’re relatively close-we need to test this theory out!! We’ll back my XR4155HC and your 50 gear up to each other, chain’em up and see who drags who!!! That’ll settle this question once and for all!!

That’s how they do it around here too!

.....but, it only proves who is heavier and/or better tires, or hitch height (who is pulling up vs down). It’s a contest of traction.
Better test would be to hook up to a heavy load (corn wagon, dump trailer, etc..) and race them up a hill; or have them plow ground, etc.. (assuming traction slippage is similar or there is none.)

 

[LouNY]

Would be a good comparison CobyRupert but I don't think it would change many minds.
Some would have objections to how it was done regardless the outcome and methods if it didn't meet their expectations.
But it would be interesting.

 

[CobyRupert]

Golly gee....would it be the transmission that “transmits” 95% of engine’s power, or the one that transmits 85%?
Hmmm...I wonder..wonder..wonder...
Oh well...I guess it’s just a big mystery!

 

[Mat4644]

No need for pulling duels. Both have been dyno tested and gear is approximately 10% more efficient and more HP delivered. Reliability testing shows HST wears faster. Repair data also shows less repairs even on glide shift gear transmissions. You also take a significant PTO HP hit.

Even with obvious gear transmission advantages my personal preference are HST drive for convenience. Even though if doing loader and material transport work one still does a fair amount of shifting with the gear ranges.

 

[Industrial Toys]

Rob.

Funny. It was one of the misleading sales tactics Deere was using marketing the 110TLB. Comparing the transmission to their hydrostat Dozer!

 

[k0ua]

Golly gee....would it be the transmission that “transmits” 95% of engine’s power, or the one that transmits 85%?
Hmmm...I wonder..wonder..wonder...
Oh well...I guess it’s just a big mystery! ��

But if both tractors are traction limited, and both are equipped with tires and weight the same, then it is not quite as clear cut on "pulling power" what ever that is. No one has defined " pulling power" to me. Now a better question would be. In plowing an acre of ground with two identical tractors one hst and one gear, which one will use more fuel per acre? That is an easy to question to answer. The hydro tractor is not as effecient as the gear tractor and therefor will use more fuel.

I contend that hooking up two equal in every way tractors drawbar to drawbar, equal heights equal tires, and equal weights (we would need to put some distributed weight on the gear tractor to be equal), I contend that they would be equal with a slight edge to the hydro tractor. Because the hydro tractor can start and apply power smoothly without breaking traction. But a lot of this would be the man operating each tractor and clutch and hydro pedal technique. Both tractors in their lowest gears are going to be traction limited. Not engine power limited NOT engine power delivered to the tires limited. NOT transmission efficiency limited. They are going to be traction limited. Someone is goin to break traction first and is going to be pulled backwards. I am betting on the gear tractor will break traction first. But it would make for an interesting spectacle. Efficiency wise, NO question gear is more efficient with less losses from prime mover to the tires. Which as far as I know has nothing to do with "pulling power". Morons that test hydro tractors in MED or HI range excluded.

 

[Industrial Toys]

Depending on the style and sophistication of a gear transmission, a simple one could cause one to stop when downshifting whereas it's not the case with a hydro, unless you have to change ranges. Stopping in a difficult spot, pulling tillage is not a great idea.

 

[dieselscout80]

Growing up on the farm, we had an old 1970's International Farmall something too. It was bigger than a IH 424, looking at old photos online, looks like it could have been an 826. I'm not sure, and I dont have any photos of it from my childhood, least not that I know of. That tractor was a hydro tractor. Lever controlled on the left side. Move the lever over and up for forward, left and back for reverse. The last time I drove that tractor was in 2005. That tractor was running strong when I left it.

That's good to hear. I think a hydro would be the best thing for mowing as one does have to be forced in to set gear splits in manual.

I have operated a IH hydro 186 and a hydro 84 and a few others when I worked for a IH dealer.